EP0095741B1 - Phosphor - Google Patents

Phosphor Download PDF

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Publication number
EP0095741B1
EP0095741B1 EP83105237A EP83105237A EP0095741B1 EP 0095741 B1 EP0095741 B1 EP 0095741B1 EP 83105237 A EP83105237 A EP 83105237A EP 83105237 A EP83105237 A EP 83105237A EP 0095741 B1 EP0095741 B1 EP 0095741B1
Authority
EP
European Patent Office
Prior art keywords
phosphor
barium
luminance
bromide
firing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP83105237A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0095741A1 (en
Inventor
Chiyuki C/O Fuji Photo Film Co. Ltd. Umemoto
Kenji C/O Fuji Photo Film Co. Ltd. Takahashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujifilm Holdings Corp
Original Assignee
Fuji Photo Film Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fuji Photo Film Co Ltd filed Critical Fuji Photo Film Co Ltd
Publication of EP0095741A1 publication Critical patent/EP0095741A1/en
Application granted granted Critical
Publication of EP0095741B1 publication Critical patent/EP0095741B1/en
Expired legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7783—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals one of which being europium
    • C09K11/779—Halogenides
    • C09K11/7791—Halogenides with alkali or alkaline earth metals
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7728—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
    • C09K11/7732—Halogenides
    • C09K11/7733—Halogenides with alkali or alkaline earth metals

Definitions

  • the present invention relates to an europium activated barium fluorohalide phosphor of the general formula I wherein
  • Europium activated barium fluorohalide phosphors are well known.
  • the divalent europium activated barium fluorohalide phosphor emits light in the near ultraviolet region at a wavelength of about 390 nm upon excitation with a radiation such as X-rays and has a high absorption efficiency for the radiation such as X-rays. Accordingly, this phosphor is employed in practical, especially as a phosphor for a radiographic intensifying screen.
  • Japanese Patent Publication No. 51(1976)-28591 describes a divalent europium activated barium fluorohalide phosphor employable for a radiographic intensifying screen wherein a portion of barium serving as the host component is replaced by other specific alkaline earth metals, having the formula: in which a, b, p, x and y are numbers satisfying the conditions of y ⁇ 0.20, x + y + p ⁇ 1, a + b ⁇ 1 and 0.001 p p ⁇ 0.20, respectively.
  • a divalent europium activated barium fluorohalide phosphor emits light when exposed to an electromagnetic wave in the wavelength region of 450-800 nm after exposure to a radiation such as X-rays, which means that the divalent europium activated barium fluorohalide phosphor is a stimulable phosphor. Accordingly, said phosphor has been recently given attention as a phosphor for a radiation image storage panel utilizing its stimulability.
  • EP-A1-0029963 describes a rare earth element activated complex halide phosphor and a radiation image storage panel having a fluorescent layer comprising the phosphor, which phosphor is represented by the formula wherein
  • the luminance of spontaneous emission of a phosphor is as high as possible.
  • the phosphor preferably gives a high luminance of spontaneous emission so as to reduce the exposure dose for a patient to as low level as possible.
  • the luminance of stimulated emission of the phosphor is as high as possible to reduce the exposure dose for a patient in the case of using the phosphor as a stimulable phosphor in a radiation image storage panel. Accordingly, enhancement in the luminance of spontaneous emission is desired for the phosphor used in a radiographic intensifying screen, and likewise enhancement of the luminance of stimulated emission is desired for the phosphor used in a radiation image storage panel.
  • the enhancement of the luminance of spontaneous emission or of the luminance of stimulated emission is of much value from a point of view of the negative effect of the radiation on the human body, even if the level of the enhancement is not so remarkable.
  • the phosphor of the present invention gives prominently high emission luminance in a near ultraviolet region in comparison with the known divalent europium activated barium fluorohalide phosphors, when exposed to a radiation such as X-rays, ultraviolet rays or cathode rays.
  • the phosphor of the present invention having the formula I also gives prominently high luminance of stimulated emission in the near ultraviolet region in comparison with the known divalent europium activated barium fluorohalide phosphors, when stimulated with an electromagnetic wave in the wavelength region of 450-800 nm after exposure to a radiation such as X-rays, ultraviolet rays or cathode rays.
  • the phosphor of the invention can be prepared, for example, by a process described below.
  • ammonium halide in which X' is F, Cl, Br or I
  • NH4X ammonium halide
  • the above-mentioned five kinds of the starting materials are, at first, mixed in the stoichiometric ratio corresponding to the formula I: wherein M, L, X, x and y have the same meanings as defined hereinbefore.
  • the mixture is prepared by initially dissolving the above-mentioned metal oxide (4) in the hydrohalogenic acid (5) and subsequently adding to the solution the barium fluoride (1), the barium halide (2), the alkali metal halide (3), the trivalent europium compound (6) and distilled water, to obtain a suspension.
  • the resulting suspension is heated under stirring and preferably under reduced pressure and/or vacuum to obtain a dry mixture.
  • the mixture is then pulverized in a mortar and is placed in a heat-resistant container such as a quartz boat, an alumina crucible or a quartz crucible, and fired in an electric furnace.
  • the temperature for the firing suitably ranges from 600 to 1000°C.
  • the firing period is determined depending upon the amount of the mixture of the starting materials for the phosphor, the firing temperature, etc., and generally ranges from 0.5 to 12 hours.
  • a weak reducing atmosphere such as a nitrogen gas atmosphere containing a small amount of hydrogen gas or a carbon dioxide gas atmosphere containing a small amount of carbon monoxide gas.
  • the trivalent europium contained in the mixture is reduced into the divalent europium under the reducing atmosphere.
  • the product obtained upon firing under the abovementioned conditions is taken out of the furnace, allowed to stand for cooling, and pulverized.
  • the pulverized product may be again placed in the container and fired, if desired.
  • the temperature for the firing suitably ranges from 500 to 800°C and the firing period suitably ranges from 0.5 to 12 hours.
  • the firing product is finely pulverized to obtain the powdery phosphor of the invention.
  • the obtained phosphor may be processed in a conventional manner involving a variety of procedures for the preparation of phosphors, for instance, a washing procedure, a drying procedure and a sieving procedure.
  • the preferred numbers for x and y in the formula I are in the ranges of 10 -2 ⁇ x Z 0.2 and 10- 5 ⁇ y ⁇ 10- 2 , respectively.
  • Fig. 1 shows the relationship between the x value and the emission luminance in terms of relative value, namely the relative luminance, for a phosphor of the present invention having the formula I.
  • Fig. 1 illustrates the relationship between the total replacing amounts (x value) of cesium and gadolinium in place of the barium (one of the host components of the phosphor), and the luminance of spontaneous emission thereof when exposed to X-rays at 80 KVp, with respect to the phosphor having the formula:
  • the emission luminance is remarkably increased when a portion of barium is replaced by a monovalent cesium and a trivalent gadolinium within the suitable range.
  • the emission luminance reaches the maximum when the replacing amount (x value) is approximately 0.1 and in contrast, is noticiably decreased where the x value is beyond 0.25.
  • the phosphor of the present invention emits light with remarkably higher luminance upon excitation with a radiation such as X-rays as compared with the known divalent europium activated barium fluorohalide phosphors.
  • the phosphor of the present invention also emits light with remarkably higher luminance upon stimulation with an electromagnetic wave in the wavelength region of 450-800 nm after exposure to a radiation, as compared with the known divalent europium divalent europium activated barium fluorohalide phosphors.
  • the phosphor of the present invention is suitably employable in a radiographic intensifying screen, as well as in a radiation image storage panel.
  • the pulverized mixture was placed in an alumina crucible, which was, in turn, placed in a high-temperature electric furnace. The mixture was then fired at 800°C for 1 hour under a carbon dioxide gas atmosphere containing a small amount of carbon monoxide. After the firing was complete, the crucible was taken out of the furnace and allowed to stand for cooling. The fired product was pulverized, placed in the alumina crucible again, and then fired at 600°C for 1 hour under a nitrogen gas atmosphere (the second firing).
  • the fired product was allowed to stand for cooling and pulverized finely to obtain a divalent europium activated barium cesium gadolinium fluorobromide phosphor powder (Ba 0.9 Cs 0.05 Gd 0.05 FBr:0.001Eu 2+ ).
  • gadolinium oxide Gd 2 0 3
  • HBr hydrobromic acid
  • H 2 0 distilled water
  • 1.76 g of cesium bromide (CsBr) and 0.228 g of europium bromide (EuBr 3 ) were added and mixed to give a suspension of the starting materials for the preparation of a phosphor.
  • Example 1 The procedure of Example 1 was repeated except for using the above prepared suspension to obtain a divalent europium activated barium caesium gadolinium fluorobromide phosphor powder (Ba 0.97 Cs 0.015 Gd 9.015 FBr:0.001Eu 2+ ).
  • gadolinium oxide Gd 2 0 3
  • HBr hydrobromic acid
  • H 2 0 distilled water
  • 11.74 g of cesium bromide (CsBr) and 0.228 g of europium bromide (EuBr 3 ) were added and mixed to give a suspension of the starting materials for the preparation of a phosphor.
  • Example 1 The procedure of Example 1 was repeated except for using the above prepared suspension to obtain a divalent europium activated barium cesium gadolinium fluorobromide phosphor powder (Ba 0.8 Cs 0.1 Gd 0.1 FBr:0.001Eu 2+ ).
  • Example 1 The procedure of Example 1 was repeated except for using the above prepared suspension to obtain a divalent europium activated barium fluorobromide phosphor powder (BaFBr:0.001Eu 2+ ).
  • the phosphors prepared in Examples 1, and 3, and Comparison Example 1 were exposed to X-rays at 80 KVp to evaluate the luminance of spontaneous emisson.
  • the pulverized mixture was placed in a quartz boat, which was, in turn, placed in a high-temperature electric furnace. The mixture was then fired at 800°C for 1 hour under a nitrogen gas atmosphere containing 3% hydrogen gas in volume. After the firing was complete, the crucible was taken out of the furnace and allowed to stand for cooling. Then the fired product was pulverized finely to obtain a divalent europium activated barium sodium gadolinium fluorobromide phosphor powder (Ba 0.9 Na 0.05 Gd 0.05 FBr:0.001Eu 2+ ).
  • gadolinium oxide Gd 2 0 3
  • HBr hydrobromic acid
  • H 2 0 distilled water
  • 1.70 g of sodium bromide (NaBr) and 0.432 g of europium bromide (EuBr 3 ) were added and mixed to give a suspension of the starting materials for the preparation of a phosphor.
  • Example 4 The procedure of Example 4 was repeated except for using the above prepared suspension to obtain a divalent europium activated barium sodium gadolinium fluorobromide phosphor powder (Ba 0.97 Na 0.015 Gd 0.015 FBr:0.001Eu 2+ ).
  • gadolinium oxide Gd 2 0 3
  • HBr hydrobromic acid
  • H 2 O distilled water
  • 110.28 g of barium bromide (BaBr 2 2H 2 0), 96.74 g of barium fluoride (BaF 2 ), 11.35 g of sodium bromide (NaBr) and 0.432 g of europium bromide (EuBr 3 ) were added and mixed to give a suspension of the starting materials for the preparation of a phosphor.
  • Example 4 The procedure of Example 4 was repeated except for using the above prepared suspension to obtain a divalent europium activated barium sodium gadolinium fluorobromide phosphor powder (Ba 0.8 Na 0.1 Gd 0.1 FBr:0.001 Eu 2+ ).
  • the phosphors prepared in Examples 4, 5 and 6 were exposed to X-rays at 80 KVp to evaluate the luminance of spontaneous emission.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Luminescent Compositions (AREA)
  • Conversion Of X-Rays Into Visible Images (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
EP83105237A 1982-05-28 1983-05-26 Phosphor Expired EP0095741B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP57089875A JPS58206678A (ja) 1982-05-28 1982-05-28 蛍光体
JP89875/82 1982-05-28

Publications (2)

Publication Number Publication Date
EP0095741A1 EP0095741A1 (en) 1983-12-07
EP0095741B1 true EP0095741B1 (en) 1987-08-12

Family

ID=13982935

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83105237A Expired EP0095741B1 (en) 1982-05-28 1983-05-26 Phosphor

Country Status (4)

Country Link
US (1) US5089170A (enrdf_load_stackoverflow)
EP (1) EP0095741B1 (enrdf_load_stackoverflow)
JP (1) JPS58206678A (enrdf_load_stackoverflow)
DE (1) DE3372984D1 (enrdf_load_stackoverflow)

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0144772B1 (en) * 1983-11-07 1990-08-01 Fuji Photo Film Co., Ltd. Phosphor, radiation image recordng and reproducing method and radiation image storage panel employing the same
JPS60139781A (ja) * 1983-12-28 1985-07-24 Fuji Photo Film Co Ltd 螢光体およびそれを用いた放射線像変換パネル
DE3574391D1 (en) * 1984-02-09 1989-12-28 Fuji Photo Film Co Ltd Phosphor, radiation image recording and reproducing method and radiation image storage panel
JPS60221483A (ja) * 1984-04-17 1985-11-06 Fuji Photo Film Co Ltd 蛍光体
JPH0629412B2 (ja) * 1984-07-10 1994-04-20 富士写真フイルム株式会社 螢光体およびそれを用いた放射線像変換パネル
DE3578081D1 (de) * 1984-09-14 1990-07-12 Konishiroku Photo Ind Verfahren zur umwandlung eines radiographischen bildes und schirm zum speichern einer strahlungsenergie mit einer anregbaren phosphorschicht.
US5028509A (en) * 1984-09-14 1991-07-02 Konica Corporation Method for converting radiographic image, radiation energy storage panel having stimulable phosphor-containing layer and alkali halide phosphor
US5514298A (en) * 1988-06-10 1996-05-07 Agfa-Gevaert, N.V. Photostimulable phosphor for use in radiography
EP0533233B1 (en) * 1991-09-17 1995-07-19 Agfa-Gevaert N.V. Photostimulable phosphor
EP0533234A1 (en) * 1991-09-17 1993-03-24 Agfa-Gevaert N.V. Radiation image recording and reproducing method
IT1256069B (it) * 1992-07-28 1995-11-27 Minnesota Mining & Mfg Metodo per registrare e riprodurre l'immagine di una radiazione, apparato usante detto metodo,pannello per la memorizzazione dell'immagine di una radiazione a fosfori fotostimolabili
DE69424981T2 (de) * 1993-10-20 2001-01-11 Agfa-Gevaert N.V., Mortsel Hochauflösendes radiographisches Aufzeichnungselement
JP2818730B2 (ja) * 1994-07-19 1998-10-30 日本原子力研究所 中性子画像形成方法
EP0747908B1 (en) 1995-06-01 1998-12-02 Agfa-Gevaert N.V. A novel class of stabilizing compounds for phosphor screens
DE69505105T2 (de) 1995-06-01 1999-04-08 Agfa-Gevaert N.V., Mortsel Neue Klasse von stabilisierenden Verbindungen für Phosphorschirme
EP0752782A1 (en) 1995-07-07 1997-01-08 Agfa-Gevaert N.V. Adjustment of the position of a scan line in a light beam scanning apparatus
EP0846962B1 (en) 1996-12-04 2001-05-30 Agfa-Gevaert N.V. An x-ray image detector and read out apparatus
EP1017062A3 (en) 1998-12-28 2001-10-04 Fuji Photo Film Co., Ltd. Radiation image conversion panel and method of manufacturing radiation image conversion panel
JP3755390B2 (ja) * 2000-09-08 2006-03-15 株式会社日立製作所 蛍光体及びそれを用いた表示装置並びに光源
JP2006300647A (ja) 2005-04-19 2006-11-02 Fuji Photo Film Co Ltd 蛍光体パネルの製造方法
JP2008185568A (ja) 2007-01-31 2008-08-14 Fujifilm Corp 放射線画像変換パネル
EP4310553A1 (en) 2022-07-19 2024-01-24 Agfa Nv Dosimeter based on nano-sized phosphor particles

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3659136A (en) * 1969-04-16 1972-04-25 Bell Telephone Labor Inc Gallium arsenide junction diode-activated up-converting phosphor
US3951848A (en) * 1975-04-28 1976-04-20 Gte Sylvania Incorporated Barium fluorochloride x-ray phosphors and method of preparing same
US4100101A (en) * 1975-09-19 1978-07-11 Gte Sylvania Incorporated Europium-activated alkaline earth fluorohalide x-ray phosphors and method for preparing the same
DE2654387C3 (de) * 1975-12-05 1979-09-13 E.I. Du Pont De Nemours And Co., Wilmington, Del. (V.St.A.) Erdalkalifluorhalogenid-Leuchtstoff
US4057508A (en) * 1976-12-01 1977-11-08 Gte Sylvania Incorporated X-ray phosphors with low afterglow
JPS5919594B2 (ja) * 1977-03-14 1984-05-07 株式会社東芝 螢光体
JPS5945706B2 (ja) * 1979-06-19 1984-11-08 大日本塗料株式会社 螢光体
EP0021342B1 (en) * 1979-06-19 1983-04-13 Kasei Optonix, Ltd. Phosphor
JPS6014786B2 (ja) * 1979-11-21 1985-04-16 富士写真フイルム株式会社 螢光体および該螢光体を用いた放射線像変換パネル

Also Published As

Publication number Publication date
JPH0412316B2 (enrdf_load_stackoverflow) 1992-03-04
DE3372984D1 (de) 1987-09-17
US5089170A (en) 1992-02-18
EP0095741A1 (en) 1983-12-07
JPS58206678A (ja) 1983-12-01

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